The present invention relates to an electrophotographic imaging device employing a continuous form sheet which has a plurality of segments divided by perforations. In this kind of imaging device. e.g., a laser beam printer or the like, an image is formed on a predetermined area of each of the segments in accordance with the image data.
Conventionally, in an electrophotographic printer, the following image Forming steps are performed:
(1) A uniformly charged circumferential surface of a photoconductive drum is exposed to light in order to form a latent image; PA1 (2) By adhering toner, the latent image is developed to a toner image; PA1 (3) The toner image is transferred onto a recording sheet at a transfer unit; and PA1 (4) The transferred image is fixed by a fixing unit. PA1 a device for discriminating whether an image is printed, in accordance with the image data, on a segment of the continuous form sheet, which is to be discharged out of the imaging device; and PA1 a device for marking the segment if it is discriminated that the segment is discharged without any image being printed in accordance with the image data. PA1 a device for discriminating whether a segment of the continuous form sheet is to be discharged out of the imaging device in a predetermined condition; and PA1 a device for marking the segment if it is discriminated that the segment is discharged in the predetermined condition.
In such a printer, printing operation is executed on a page basis. Accordingly, if a continuous form sheet, having a plurality of pages defined by perforations, is employed as a recording medium, an image is formed on a predetermined area of each page. When the printing operation is completed and the printer is set into a stand-by state, feeding of the continuous form sheet is stopped such that the perforation is located at a fixing position. At this stage, if the distance between the fixing position and a transferring position does not correspond to the length of a page of the sheet, there would be a blank page on which no image is printed between the fixing unit and the transferring unit. With this condition, if the succeeding printing operation is restarted, the blank page is discharged from the printer as it is.
A common problem with such a printer is that it is difficult to determine whether the discharged page is not printed due to the pause between two different printing operations, or due to some trouble in the printing operation.